多线程中this、Thread.currentThread() 和 this.currentThread()的区别

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结论：

• Thread.currentThread()：获取当前线程的引用，既代码段正在被哪一个线程调用。
• this：指当前对象
• this.currentThread()：与Thread.currentThread()一致，都是调用

实验代码：

public class CountOperate extends Thread {
	
    public CountOperate() {
		System.out.println("=========CountOperate start============");
		System.out.println("Thread.currentThread().getName() = " + Thread.currentThread().getName());
		System.out.println("Thread.currentThread().isAlive() = " + Thread.currentThread().isAlive());
		System.out.println("this.getName() = " + this.getName());
		System.out.println("this.isAlive() = " + this.isAlive());
		System.out.println("this.currentThread().getName() = " + this.currentThread().getName());
		System.out.println("this.currentThread().isAlive() = " + this.currentThread().isAlive());
		System.out.println("=========CountOperate end  ============");
	}

	@Override
	public void run() {
		System.out.println("=========run start============");
		System.out.println("Thread.currentThread().getName() = " + Thread.currentThread().getName());
		System.out.println("Thread.currentThread().isAlive() = " + Thread.currentThread().isAlive());
		System.out.println("this.getName() = " + this.getName());
		System.out.println("this.isAlive() = " + this.isAlive());
		System.out.println("Thread.currentThread() == this " + (Thread.currentThread() == this));
		System.out.println("this.currentThread().getName() = " + this.currentThread().getName());
		System.out.println("this.currentThread().isAlive() = " + this.currentThread().isAlive());
		System.out.println("=========run end  ============");
	}	
}

实例一：

public class TestCountOperate {
	public static void main(String[] args) {
		CountOperate countOperate = new CountOperate();
		countOperate.start();
	}
}

结果：

=========CountOperate start============
Thread.currentThread().getName() = main
Thread.currentThread().isAlive() = true
this.getName() = Thread-0
this.isAlive() = false
this.currentThread().getName() = main
this.currentThread().isAlive() = true
=========CountOperate end  ============
=========run start============
Thread.currentThread().getName() = Thread-0
Thread.currentThread().isAlive() = true
this.getName() = Thread-0
this.isAlive() = true
Thread.currentThread() == this true
this.currentThread().getName() = Thread-0
this.currentThread().isAlive() = true
=========run end  ============

实例二：

public class TestCountOperate {
	public static void main(String[] args) {
		CountOperate countOperate = new CountOperate();
		Thread thread = new Thread(countOperate);
		thread.setName("A");
		thread.start();
	}
}

结论：

=========CountOperate start============
Thread.currentThread().getName() = main
Thread.currentThread().isAlive() = true
this.getName() = Thread-0
this.isAlive() = false
this.currentThread().getName() = main
this.currentThread().isAlive() = true
=========CountOperate end  ============
=========run start============
Thread.currentThread().getName() = A
Thread.currentThread().isAlive() = true
this.getName() = Thread-0
this.isAlive() = false
Thread.currentThread() == this false
this.currentThread().getName() = A
this.currentThread().isAlive() = true
=========run end  ============

      将线程对象countOperate 以构造参数的方式传递给Thread对象进行start（）启动线程，我们直接启动的线程实际是thread，而作为构造参数的countOperate，赋给Thread类中的属性target，之后在Thread的run方法中调用target.run()；此时Thread.currentThread()是Thread的引用thread, 而this依旧是CountOperate的引用，所以是不一样的，打印的内容也不一样。

本文标签： 多线程区别threadcurrentThread